Re: [Exim] bare linefeeds in SMTP

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Author: Pat Lashley
Date:  
To: exim-users
Subject: Re: [Exim] bare linefeeds in SMTP
First off, I'd like to say that I'm in complete agreement with
Philip's arguments. But I would like to inject one extremely
minor technical correction nit.

Technically, the line terminator used by Exim is not LF (Line Feed),
it is NL (New Line). Same binary value, different semantics. Here
are the relevant descriptions from ANSi X3.4-1977 (American National
Standard Code for Information Interchange)

    5. Definitions


    ...


    5.2 Control Characters


    ...


    0/10 LF (Line Feed) A format effector that advances
    the ative position to the same character position on
    the next line.  Where appropriate, this character may
    have the meaning "New Line" (NL), a format effector
    that advances the active position to the first character
    position on the next line.  Use of the NL convention
    requires agreement between sender and recipient of
    data.


    ...


    0/13 CR (Carriage Return (Return)).  A format effector
    that moves the active position to the first character
    position on the same line.



So the network transmission standard of CR LF and the Exim/Unix
usage of NL are both well within the standard. (But MicroSoft's
use of CR is not. Big surprise.)

Perhaps those who believe Exim should use CR LF internally would
be more comfortable thinking of the octet it does use as NL
instead of LF...



-Pat